Ray Donovan writer-producer Brett Johnson has teamed with the Showtime series’ executive producer Bryan Zuriff on another crime drama project for the pay cable network. The untitled period one-hour, written by Johnson, is executive produced by Leonardo DiCaprio through his company Appian Way.

Set in 1980s Brooklyn, the drama traces a decade-long relationship between an unstable mafia captain and a rogue federal agent, each violating the strict codes of their respective organizations. It examines the corrosive power the Wall Street era had on both the mafia and the FBI. Johnson and Zuriff are executive producing alongside Appian Way’s Leonardo DiCaprio and Jennifer Davisson as well as Charles Pacheco and Jennifer Erwin.

Developing his own show marks another milestone for Johnson, who willed his way into TV writing with a gig on one of the most acclaimed drama series of the past decade.

Johnson was the video archivist at management/production company Industry Entertainment while pursuing feature writing. As a viewer, he fell in love with AMC’s Mad Men and, after finding out that one of the writers assistants co-wrote the Season 1 finale with creator Matthew Weiner, he became determined to get on the show. Johnson walked into the office of Industry Entertainment partner Keith Addis — who Weiner’s manager was at the time — and asked Addis to get him an assistant job on Mad Men for Season 2. In response, Addis told him he didn’t know who he was.

Johnson persisted, and after pestering Addis for three months, the manager finally arranged for Johnson to meet with Weiner, who hired him as a script coordinator. Johnson became head of research and, when Weiner decided to incorporate the JFK assassination into the show, Johnson spent months researching the event. That led to Weiner assigning Johnson to co-write that episode — 2009’s The Grown-Ups — with him. It was Johnson’s first produced script, and it earned him a WGA Award nomination alongside Weiner.

After three seasons on Mad Men, Johnson segued to Showtime’s Ray Donovan, where he also has been for three seasons, rising to producer. Johnson has shared in four WGA series nominations: three for Mad Men — two of which resulted in wins — and one for Ray Donovan. He is repped by WME.